The attachment to battery tabs of a connecting conductor is relatively easy where the tab metal is reasonably thick and it does not contact a layer of low melting point plastic. Resistance welding or laser welding provide comparatively easy solutions. For example, Morris used spot welding for his battery's tabs (U.S. Pat. No. 5,585,206). Narukawa et al. used ordinary laser welding to both connect the tab collector to the casing and to seal the casing. The problem which this invention solves is the attachment of tabs to the conducting metal of the battery, such as in the battery of a co-pending U.S. patent application, Ser. No. 09/289,071. In that battery, the metal conducting layers of the positive and negative electrodes are in the range of 0.3 to 3 .mu.m and adhere to a thin layer of polyimide which might be about 9 .mu.m thick. Consequently, extreme care is required, otherwise the polyimide plastic will melt leading to short circuits within the battery, and the conducting metal itself may also be damaged. Therefore, a small controlled amount of external energy must be used to effect the attachment or bonding.